Semiconductor manufacturing has seen a reduction in critical dimension (CD) and an exponential increase in the cost of multiple patterning. The semiconductor manufacturing industry is transitioning to extreme ultraviolet lithography (EUV) patterning to enable smaller CD features obtained with fewer processing steps. In many cases, the EUV photo resist (PR) material is patterned onto a silicon-based material with an aspect ratio of about 2:1.
During the EUV process, an undesired effect may occur when non-uniformities lead to aspect ratio variation across the wafer. Another problem may arise during semiconductor manufacturing with EUV when the pattern transfer to the under layers is limited to the ability of the EUV PRs to withstand the etch processes defining the pattern. As a result, the EUV PR is quickly consumed and cannot be effectively used to define deep patterns within the wider layer.
Another problem is that very thick EUV PRs are required to successfully transfer the pattern successfully to the under layer, but this may lead to line bending (e.g., collapse of the EUV PR lines) or poor selectivity (loss of CD) as the EUV may not penetrate all the way to the bottom of the line.
The background description provided herein is for the purposes of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.